Re: Performance degradation in commit ac1d794

On 2015-12-26 12:22:48 +0100, Andres Freund wrote:
> > > 3) Replace the postmaster_alive_fds socketpair by some other signalling
> > >    mechanism. E.g. sending a procsignal to each backend, which sets the
> > >    latch and a special flag in the latch structure.
> > 
> > And what would send the signal?  The entire point here is to notice the
> > situation where the postmaster has crashed.  It can *not* depend on the
> > postmaster taking some action.
> 
> Ahem. Um. Look, over there --->
> 
> I blame it on all the food.

A unportable and easy version of this, actually making sense this time,
would be to use prctl(PR_SET_PDEATHSIG, SIGQUIT). That'd send SIGQUIT to
backends whenever postmaster dies.  Obviously that's not portable
either - doing this for linux only wouldn't be all that kludgey tho.